/Engine/Source/Editor/SubobjectEditor/Public/SSubobjectEditor.h
[TOptional](API\Runtime\Core\IO\TOptional)< EItemDropZone > HandleOnCanAcceptDrop ( const [FDragDropEvent](API\Runtime\SlateCore\Input\FDragDropEvent) & DragDropEvent, EItemDropZone DropZone, FSubobjectEditorTreeNodePtrType TargetItem )